Home / Standards / GB/T 8 GB/T 8 Active Square head bolts—Product grade C 方头螺栓 C级 Standard Type GBT ICS 21.060.10 CCS J13 Status 现行 Issue Date 2021-12-31 Implementation 2022-07-01 Responsible Dept 中国机械工业联合会 Drafting Unit 中国机械工业联合会